There are many electronic devices that have digital cameras with relatively large displays for a user to perceive the image that is being seen by the digital camera. This includes smart phones, or other types of iPOD-type devices, and also certain types of tablet computers. Such devices could be used to detect a laser beam, including visible laser light in either the red or green spectra. Also some digital cameras are sensitive enough to perceive infrared lasers and can give a certain visible output when receiving infrared laser signals, as well.
The width of the laser beam needs to be considered; typical laser transmitters used for indicating on-grade elevation on construction jobsites have a width in the range of two millimeters to five millimeters. The size of the lens for most digital cameras on smart phones and iPODs is about the same size, so there will need to be some type of special software to help in determining the center of the beam density. An application program that can be loaded onto the smart phone (or other smart device) will be needed to assist the user in determining the position of the laser beams, and such an APP program can also be used to provide other very useful optional features.